The present invention relates to a device for skiving and roller burnishing a work piece.
Skiving tools are usually used to accurately cut small quantities of material from the inner wall of a cylindrical hole. The skiving tool first cuts or shaves off a small amount of material, normally between 0.020 and 0.040 inch on the diameter, from the hole and then a roller burnishing tool, burnishes the hole to a smooth finish.
During skiving operations, scrap in the form of "chips" is produced. These chips may be in the form of a long flat ribbon-like string or small pieces. Strings of chips are difficult to handle. They may become entangled with each other or wrap around the chip conveyor, making it difficult for removal by the chip conveyor from the machine. It is also common for strings of chips to accumulate in the exit chamber of the device resulting in overloading, jamming or damage to the conveyor.
It is generally necessary to provide manual intervention to move strings of chips from a conveyor into a container. To avoid handling strings of chips, some skiving and roller burnishing devices are designed to produce chips having a small cross-section and length by using an assortment of various size interchangeable carbide chipbreakers. This is a major disadvantage when machining workpieces, such as hydraulic cylinders with oil port holes. These small chips can enter these openings and then fall into the rollers or pads on the skiving, roller burnishing tool, thus causing damage to both the tool and workpiece. When this occurs the workpiece is rendered unusable. Also a much higher coolant pressure is required to force this small chip ahead of the tool and from workpiece.
In some skiving and roller burnishing devices, such as employed by the assignee of the present invention, the skiving and roller burnishing device is designed to cut a greater mass, up to 0.5 inch on diameter, at a faster rate than other cutting devices while still maintaining the precision machining related to skiving and roller burnishing. However, it is common to produce chips in the assignee's skiving and roller burnishing devices having a flat ribbon-like configuration, greater surface area and dimensions of 0.375-0.750 inch wide and 0.010-0.015 inch thick. Thus, the chips produced by the assignee's device must be in the form of long strings which cannot be easily broken by a carbide chipbreaker.